ornithine

American  

[awr-nuh-theen] / ˈɔr nəˌθin /

noun

Biochemistry.

1. an amino acid, H 2 N(CH2 ) 3 CH(NH2 )COOH, obtained by the hydrolysis of arginine and occurring as an intermediate compound in the urea cycle of mammals.

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ornithine British  

/ ˈɔːnɪˌθiːn /

noun

1. an amino acid produced from arginine by hydrolysis: involved in the formation of urea in the liver; diaminopentanoic acid. Formula: NH 2 (CH 2 ) 3 CHNH 2 COOH

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ornithine Scientific  

/ ôr′nə-thēn′ /

1. An amino acid not found in proteins, formed by hydrolyzing arginine and important in the formation of urea. Chemical formula: C ₅ H ₁₂ N ₂ O ₂ .

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Etymology

Origin of ornithine

1880–85; ornith(uric acid) , secreted by birds + -ine ²

Example Sentences

By using stable isotope tracers and analyzing gene expression, the researchers showed that S. gordonii releases a substance called ornithine that prompts F. nucleatum to produce more of a molecule called polyamine.

From Science Daily • Feb. 15, 2024

Hence, the urea cycle is also referred to as the ornithine cycle.

From Textbooks • Jun. 9, 2022

Gelsinger died during a clinical trial to cure ornithine transcarbamylase deficiency, a genetic condition that he suffered from.

From Scientific American • Feb. 12, 2021

The molecule urea is formed as a by-product of the conversion of arginine to ornithine.

From Nature • Mar. 17, 2020

The precursors are two essential amino acids, argenine and ornithine and certain vitamins such as C and B 6.

From How and When to Be Your Own Doctor by Solomon, Steve